Abstract:

Objective

To investigate the imaging characteristics of hepatic lipid-poor perivascular epithelioid cell tumor （PEComa）.

Methods

A retrospective analysis was conducted on the clinical， pathological and imaging data of 12 patients with hepatic lipid-poor PEComa diagnosed by surgical pathology in the Department of Hepatobiliary Surgery at Xiangyang Central Hospital from January 2016 to December 2024，and the relevant literatures were reviewed.

Results

All 12 patients with hepatic lipid-poor PEComa were female， with a mean age of （48.58±10.96） years old. The tumors were all solitary， among which 4 cases were located in the left lobe of the liver， and 8 cases were located in the right lobe. The clinical manifestations included abdominal distension and discomfort （2 cases）， abdominal pain （1 case） and back pain （1 case）， and while 8 cases were asymptomatic. In terms of imaging， all cases showed significant enhancement during the arterial phase of enhanced scan. Among them， the enhancement degrees of 10 cases gradually diminished in the portal vein phase and delayed phase， which was in line with the typical "fast-in and fast-out" or "fast-in and slow-out" enhancement patterns. The remaining 2 cases showed persistent enhancement during the portal vein stage and the delayed stage， and were classified as the "persistent"enhancement pattern. In the arterial phase of enhanced scanning， thickened vascular shadows could be seen in or around the lesions in 9 patients with PEComa. Pathologically， the tumor tissue lacked mature adipocytes and was mainly composed of a large number of epithelioid cells， which were radially arranged around the vascular lumen. Immunohistochemical staining showed positive expressions of HMB-45， Melan-A and smooth muscle actin.

Conclusion

Hepatic lipid-poor PEComas exhibit unique imaging and pathological characteristics， which are of significant clinical value for the early diagnosis and differential diagnosis of this disease.

Key words: Hepatic tumor, Perivascular epithelioid cell tumor, Computed tomography, Magnetic resonance imaging